Chi Cheuk Tsang

Office: 1087 Evans
E-mail: chicheuk at

I am a fifth year PhD student in the UC Berkeley math department. I am interested in low-dimensional topology. More specifically, I like thinking about 3-manifolds, their geometry, and flows and foliations on them.

My advisor is Ian Agol.

Starting in Fall 2023, I will be a postdoc at the Centre de recherches mathématiques.

I received my BSc in mathematics from Chinese University of Hong Kong in 2018.

I am coorganizing the student 3-manifold seminar with Eduardo Reyes in Spring 2023.

Here is my CV.



  1. Chi Cheuk Tsang; "On the set of normalized dilatations of fully punctured pseudo-Anosov maps", In preparation
  2. Michael Landry and Chi Cheuk Tsang; "Endperiodic maps, splitting sequences, and branched surfaces", Preprint (2023). arXiv:2304.14481
  3. Eriko Hironaka and Chi Cheuk Tsang; "Standardly embedded train tracks and pseudo-Anosov maps with minimum expansion factor", Preprint (2022). arXiv:2210.13418
  4. Chi Cheuk Tsang; "Constructing Birkhoff sections for pseudo-Anosov flows with controlled complexity", Preprint (2022). arXiv:2206.09586
  5. Chi Cheuk Tsang; "Veering branched surfaces, surgeries, and geodesic flows", Preprint (2022). arXiv:2203.02874
  6. Ian Agol and Chi Cheuk Tsang; "Dynamics of veering triangulations: infinitesimal components of their flow graphs and applications", Algebraic and Geometric Topology, to appear. arXiv:2201.02706
  7. Ki Fung Chan, Spiro Karigiannis, and Chi Cheuk Tsang; "The LB-cohomology on compact torsion-free G2 manifolds and an application to "almost" formality"; Annals of Global Analysis and Geometry 55 (2019), 325-369. DOI:
  8. Ki Fung Chan, Spiro Karigiannis, and Chi Cheuk Tsang; "Cohomologies on almost complex manifolds and the ∂-lemma"; Asian Journal of Mathematics 23 (2019), 561-584. DOI:

Selected talks:

Postcards that I made for NCNGT 2021 and NCNGT 2022.

Some computational resources:

Some figures from drafts of papers and other random math sketches.

Qual resources

The syllabus and transcript for my qualifying exam.

I worked through some textbook exercises when preparing for my quals. Here are some hand-written solutions to problems I found interesting. The first page of each pdf records which questions are included. Disclaimer: I do not guarantee correctness of the solutions.